Over the years, there has been a continuing need for variable output AC power sources. Application of such variable output AC power sources includes driving reactive loads. Some examples of such reactive loads include electric motors, ballasts for discharge-based lighting (e.g. high-pressure sodium vapor luminaries that may be used in street lighting) and other various types of applications. Because of the pressing need for a variable output AC power source, a wide range of solutions has been developed ranging from auto transformers to sophisticated pulse width modulated (PWM) power controllers. It is in this prior-art rich environment that the present method and apparatus is distinguished in terms of its ability to deliver substantially pure sinusoidal power to such reactive loads at higher levels of efficiency.